Summary Content
Carbon farming refers to changes in farm practices that increase carbon sequestration, offering farmers potential payments through carbon credits. While carbon credit policies remain uncertain, this approach could provide added income for farmers while encouraging sustainable practices. Minnesota’s low adoption of cover crops and reduced tillage means the potential for change is significant. Key questions include: 1) How much carbon can be sequestered using no-till and cover crops in Minnesota? and 2) How do these practices impact crop yields?
Given the evolving and complex carbon sequestration and Carbon Intensity (CI) score markets, farmers face challenges in evaluating contract options. This project also supports UMN Extension education to help farmers navigate carbon and CI monetization.
Field trials were conducted at a long-term site near Wells, MN, where drainage regimes (established in 2012) and three tillage treatments (conventional, strip-till, and no-till, added in 2017) are evaluated. The site’s eight blocks – half drained, half undrained – create 16 unique treatment combinations to assess the cumulative effects on soybean yield and soil properties over eight seasons.
Soils were analyzed for carbon and health indicators to assess how tillage and drainage influence soil physical and chemical traits. Additionally, we began building an Extension program focused on carbon and CI contracts. While changing federal guidelines (e.g., 45Z regulations) have slowed the process, we are building materials and working with experts to clarify opportunities for Minnesota producers.
Findings
Drainage and tillage had strong effects in 2024 due to rainfall patterns. Drained soybean plots averaged 65 bu/ acre; undrained, 51. Conventional tillage averaged 66 bu/ acre; strip-till, 58; no-till, 50. Soybeans after baled corn stalks yielded 61 bu/acre versus 56 with retained stalks. Additional composition and corn yield data are in the full report.
Soil health data included pH, organic matter, nutrients, and advanced carbon indicators. While most measures weren’t significantly affected, pH, WAS, Min_C, and WEO_C were influenced by tillage, drainage, or rotation.
On the education side, CI scores for real-world Minnesota cropping systems were developed with help from Cates and EOR. Policy uncertainty complicated finalizing outreach materials. However, farmer interest remains strong, as shown during discussions at the Soil Management Summit. Next steps include applying a public GREET modeling tool to estimate CI under various management scenarios. These will be presented at the Sept. 9, 2025, field day in Wells.
This long-term research site offers valuable insights into how tillage, drainage, and residue management affect yield, soil health, and profitability. While some soil metrics remain stable, 2024 results reinforce the importance of drainage and tillage. As interest in carbon markets grows, this research provides essential science-based guidance to help Minnesota farmers increase profits while supporting environmental goals.
